cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A048193 Number of chordal graphs (or triangulated graphs) on n vertices.

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%I A048193 #28 Feb 16 2025 08:32:39
%S A048193 1,2,4,10,27,94,393,2119,14524,126758,1392387,19109099,326005775,
%T A048193 6905776799,181945055235
%N A048193 Number of chordal graphs (or triangulated graphs) on n vertices.
%C A048193 Graphs having no induced cycles of any length > 3, so every cycle in the graph has a chord, or is "triangulated".
%C A048193 All such graphs are perfect.
%C A048193 Euler transform of A048192. - _Eric M. Schmidt_, Mar 25 2015
%C A048193 Conjectured partial sums of A079456. - _Sean A. Irvine_, Jun 25 2022
%H A048193 S. Hougardy, <a href="http://www.or.uni-bonn.de/~hougardy/">Home Page</a>
%H A048193 S. Hougardy, <a href="http://dx.doi.org/10.1016/j.disc.2006.05.021">Classes of perfect graphs</a>, Discr. Math. 306 (2006), 2529-2571.
%H A048193 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ChordalGraph.html">Chordal Graph</a>
%F A048193 a(n) = A048192(n) + A287427(n).
%Y A048193 Cf. A048192 (connected chordal graphs).
%Y A048193 Cf. A287427 (disconnected chordal graphs).
%Y A048193 Cf. A048194.
%K A048193 nonn,more
%O A048193 1,2
%A A048193 _Gordon F. Royle_
%E A048193 Edited by _N. J. A. Sloane_, Jul 04 2008
%E A048193 a(12) added (using A048192) by _Eric M. Schmidt_, Mar 25 2015
%E A048193 a(13) and a(14) added (using A048192) by _Falk Hüffner_, Jan 15 2016
%E A048193 a(15) added (using A048192) by _Jakub Jablonski_, Sep 15 2020